JP2008148490A - Rotating machine drive system, washing machine, and method for confirming winding switching result of rotating machine - Google Patents

Abstract

The present invention provides a rotating machine drive system capable of determining whether or not the connection state of windings in a rotating machine has been switched, a washing machine configured with the system, and a method for confirming the result of switching the windings of the rotating machine.
When a connection state of a stator winding of a motor is changed by relays to change an induced voltage constant of the winding, a control microcomputer changes the connection state of the winding. Make sure you did. Specifically, when the motor 15 is stopped, the change in the resistance value of the winding 18 before and after the relay is operated is compared. When the motor 15 is rotated, the magnetic pole position estimator 39 is used before and after the relays 62 to 64 are operated. The estimated change in induced voltage Ed is compared.
[Selection] Figure 1

Description

  The present invention relates to a system for driving a rotating machine configured to have a plurality of induced voltage constants by changing a connection state of a stator winding, a washing machine configured with the system, and a rotation The present invention relates to a method for confirming a result of winding switching of a machine.

  As shown in FIG. 5, the driving state of a motor used in a washing machine or a washing / drying machine is high torque and low rotation speed during washing, and low torque and high rotation speed during dehydration and drying. However, in a washing machine that is a consumer device, there is a limit to increasing the current depending on the power supply standard. For this reason, the induced voltage constant needs to be set to be large so as to compensate for the shortage of current in the driving state where high torque and low rotation speed, which originally requires a large amount of current, are required. However, if the induced voltage constant of the motor is set to be large, there arises a problem that it becomes difficult to obtain a high rotational speed at the time of dehydration or the like.

In particular, in a direct drive type washing machine, the difference in motor rotation speed between washing and dehydration becomes extremely large, so mismatch between the electric constant of the motor and the driving state of the load increases power consumption or increases efficiency. Since the effect on the decrease is large, it has been a problem that cannot be ignored.
In order to solve such a problem, in Patent Document 1, the connection of the stator windings is switched so that the induced voltage constant is optimized corresponding to the driving state of the motor.
JP 2003-18879 A

Here, in order to switch the connection of the stator windings of the motor, specifically, a switch such as a relay is generally used. However, since contact welding may occur in the relay, for example, even if the microcomputer outputs a contact switching energization command, the possibility that the contact is not actually switched cannot be denied.
The present invention has been made in view of the above circumstances, a rotating machine drive system capable of determining whether or not the connection state of the windings in the rotating machine has been switched, a washing machine configured with the system, and An object of the present invention is to provide a method for confirming the result of switching the winding of a rotating machine.

The rotating machine drive system according to claim 1, wherein the rotating machine is configured to have a plurality of induced voltage constants by changing a connection state of the stator windings;
A changeover switch for changing the connection state of the windings;
In addition to controlling the opening and closing of the changeover switch, a changeover result confirmation means for confirming that the connection state of the winding has been changed by the control is provided.
If comprised in this way, the switching result confirmation means can confirm whether the connection state of the stator winding | coil in a rotary machine changed according to opening and closing of a changeover switch.

  A washing machine according to a sixth aspect includes the rotating machine drive system according to any one of the first to fifth aspects, wherein the washing operation and the dehydrating operation are performed by a driving force generated by the rotating machine. That is, in the washing or rinsing operation of the washing machine, it is required to drive the motor at a low speed and a high output torque, and in the dehydration operation, the motor is required to be driven at a high speed and a low output torque. Therefore, in order to optimally cope with each driving state, it is desirable to switch so as to set different induced voltage constants in the stator winding, so that the application of the present invention is effective.

According to the rotating machine drive system of the first aspect, since it can be confirmed whether or not the connection state of the stator winding has changed, it is possible to prevent the rotating machine from operating without actually changing the connection state. .
According to the washing machine of the sixth aspect, in a configuration in which washing or rinsing operation or dehydration operation is optimally performed using one motor, a change in the connection state of the stator windings of the motor is confirmed and normal operation is performed. It can be carried out.

  Hereinafter, an embodiment in which the rotating machine control system of the present invention is applied to a drum type washing machine will be described with reference to FIGS. First, the overall configuration of the drum type washing machine will be described with reference to FIG. A door 3 is provided at the front of the outer box (housing) 2 that forms the outer shell of the drum-type washing machine 1, and a number of switches and display units (none of which are shown) are provided at the top. An operation panel 4 is provided. The door 3 opens and closes a laundry loading / unloading port 5 formed in the front center portion of the outer box 2.

  A cylindrical water tank 6 is disposed inside the outer box 2. The water tank 6 is disposed in a horizontal axis shape in which the axial direction is the front-rear direction (left-right direction in FIG. 3) and is inclined upward, and is elastically supported by an elastic support device 7. A cylindrical drum 8 is disposed coaxially with the water tank 6 inside the water tank 6. The drum 8 functions as a shared tank for washing and dehydration and drying. A large number of small holes 9 are formed in almost the entire region of the drum (only a part is shown in FIG. 3). A plurality of baffles 10 are provided on the periphery (only one is shown in FIG. 3).

The aquarium 6 and the drum 8 have openings 11 and 12 for loading and unloading the laundry on the front surface, respectively. The opening 11 of the aquarium 6 is connected to the laundry loading and unloading opening 5 in a watertight manner by a bellows 13, and the drum 8 The opening 12 faces the opening 11 of the water tank 6. A balance ring 14 is provided around the opening 12 of the drum 8.
A motor 15 (corresponding to a rotating machine) for rotating the drum 8 is disposed on the back surface of the water tank 6. The motor 15 is an outer rotor type brushless DC motor (permanent magnet synchronous motor), and a stator (stator) 16 is attached to an outer peripheral portion of a bearing housing 17 attached to a central portion of the back portion of the water tank 6. A three-phase winding 18 (corresponding to a stator winding) is wound around the stator 16.

  A rotor (rotor) 19 of the motor 15 is disposed so as to cover the stator 16 from the outside, and a rotary shaft 20 attached to the center is rotatably supported by the bearing housing 17 via a bearing 21. The front end portion of the rotating shaft 20 protruding from the bearing housing 17 is connected to the central portion of the back portion of the drum 8. That is, when the rotor 19 of the motor 15 rotates, the drum 8 is also rotated integrally with the rotor 19 (so-called direct drive system), and a rotational force is applied to the laundry accommodated in the drum 8. Thus, a washing operation, a rinsing operation, and a dehydrating operation are performed.

A water reservoir 22 is provided on the lower surface of the water tank 6, a heater 23 for washing water is disposed inside the water reservoir 22, and a drainage hose is disposed at the rear of the water reservoir 22 via a drain valve 24. 25 is connected.
A hot air generator 26 is provided at the top of the water tank 6, and a heat exchanger 27 is provided at the back. The hot air generating device 26 includes a hot air heater 29 disposed in a case 28, a fan 31 disposed in a casing 30, and a fan motor 33 that rotationally drives the fan 31 via a belt transmission mechanism 32. The case 28 and the casing 30 are communicated with each other. A duct 34 is connected to the front portion of the case 28, and the front end portion of the duct 34 projects to the front portion in the water tank 6 and faces the opening 12 of the drum 8.

Here, warm air is generated by the warm air heater 29 and the fan 31, and the warm air is supplied into the drum 8 through the duct 34. The warm air supplied into the drum 8 heats the laundry in the drum 8 and removes moisture, and is discharged to the heat exchanger 27 side.
The heat exchanger 27 has an upper part communicating with the inside of the casing 30 and a lower part communicating with the inside of the water tank 6. Water is poured from the upper part and flows down to cool water vapor in the air passing through the inside. It is a water-cooled type that condenses and dehumidifies. The air that has passed through the heat exchanger 27 is returned to the hot air generator 26 again, and is warmed and circulated.

  FIG. 1 is a functional block diagram showing a configuration of a control device 35 that vector-controls the rotation of the motor 15. Here, the components excluding the control microcomputer 36 and the inverter circuit 37 described later are realized by software processing executed by a DSP (Digital Signal Processor). Further, a rotation drive control means is realized by the control microcomputer 36 and the DSP. The DSP includes an input / output port, a serial communication circuit, an A / D converter for inputting an analog signal such as a current detection signal, a timer for performing PWM processing, and the like.

  A control microcomputer (switching result confirmation means, stop time confirmation means, drive time confirmation means) 36 that controls the overall operation of the washing machine 1 controls the washing operation, the rinsing operation, and the dehydration operation according to the washing course, and performs the washing. The command rotational speed ωref according to the operation mode corresponding to the course is output. The subtractor 38 outputs a rotational speed deviation Δω that is a subtraction result between the command rotational speed ωref and a detected rotational speed ω of the motor 15 obtained from a magnetic pole position estimator (driving time confirmation means) 39 described later. ing.

  The proportional integrator 40 performs a proportional integral calculation with the rotational speed deviation Δω as an input, and the dq distributor 41 generates a d-axis current command value Idref and a q-axis current command value Iqref from the proportional-integral calculation result. It has become. Here, the d-axis current and the q-axis current are respectively an excitation current and a torque current that are represented by a rotating coordinate system that rotates with a rotational phase angle θ with respect to the stationary coordinate system (αβ coordinate system). .

  The subtractors 42 and 43 output current deviations ΔId and ΔIq, which are subtraction results between the current command values Idref and Iqref and the d-axis current value Id and q-axis current value Iq output from the coordinate converter 46, respectively. is there. The proportional integrators 44 and 45 receive the current deviations ΔId and ΔIq, respectively, and perform a proportional integral calculation to generate a d-axis voltage command value Vd and a q-axis voltage command value Vq.

  A winding resistance detector 47 (corresponding to a stop time confirmation means and a winding resistance detection means) applies a constant voltage to the winding 18 of the motor 15 when the control microcomputer 36 starts up the motor 15. The resistance R of the winding 18 is calculated from the applied d-axis voltage command value Vd and q-axis voltage command value Vq and the d-axis current value Id and q-axis current value Iq output from the coordinate converter 46. ing. When the motor 15 is started, the control microcomputer 36 activates the winding resistance detection permission signal Sp (hereinafter referred to as the permission signal Sp) by setting the winding resistance R to H level when the command rotational speed ωref is 0. After the detection is completed, the permission signal Sp is invalidated by setting it to L level, and then the command rotational speed ωref is gradually increased in the positive direction (during forward rotation) or in the negative direction (during reverse rotation).

  The coordinate converter 48 receives the voltage command values Vd and Vq from the winding resistance detector 47 when the permission signal Sp is at the H level, and receives the voltage command value Vd from the proportional integrators 44 and 45 when the permission signal Sp is at the L level. , Vq. Based on the rotation phase angle θ, the input voltage command values Vd and Vq of the rotating coordinate system are converted into voltage command values Vα and Vβ of the stationary coordinate system. The PWM generator 49 converts the voltage command values Vα and Vβ into voltage command values Vu, Vv, and Vw by two-phase to three-phase conversion, and based on these, converts the PWM signals Vup, Vun, Vvp, Vvn, Vwp, and Vwn. The signal is output to the inverter circuit 37.

  The inverter circuit 37 (corresponding to power conversion means) has a configuration in which six IGBTs 50 (corresponding to semiconductor switching elements) are connected in a three-phase full bridge, and the DC power supply lines 51 and 52 are connected to the converter 53. A DC voltage obtained by double-voltage full-wave rectification of an AC power supply of 100 V is applied.

  Current detectors 54 and 55 (corresponding to current detection means) are Hall CTs provided on the output line of the inverter circuit 37, and any two of the three phases, for example, the current Iv of the V phase and the W phase, Iw is detected. The current detection signals from the current detectors 54 and 55 are input to an A / D converter (not shown) inside the DSP and converted into digital data. The three-phase / two-phase converter 56 calculates a U-phase current Iu from the currents Iv, Iw, and converts the three-phase currents Iu, Iv, Iw into two-phase currents Iα, Iβ. . The coordinate converter 46 converts the currents Iα and Iβ in the stationary coordinate system into currents Id and Iq in the rotational coordinate system based on the rotational phase angle θ output from the magnetic pole position estimator 39. .

  The magnetic pole position estimator 39 (corresponding to the rotational position estimating means) outputs the d-axis current value Id and q-axis current value Iq output from the coordinate converter 46 and the proportional integrators 44 and 45 when the motor 15 rotates. Based on the d-axis voltage command value Vd and q-axis voltage command value Vq and the motor constants R, Ld, Lq, the magnetic pole position of the rotor 19, that is, the rotational phase angle θ and the rotational speed ω are estimated. Of the motor constants, the winding resistance R uses a value detected by the winding resistance detector 47, and the inductances Ld and Lq use values measured in advance or design values.

The magnetic pole position estimator 39 obtains the induced voltage estimated values Eds and Eqs by the following equations (1) and (2). Here, p is a differential operator.
Eds = Vd−R · Id−Ld · pId + ω · Lq · Iq (1)
Eqs = Vq-ω.Ld.Id-R.Iq-Lq.pIq (2)
Then, the rotational speed ω is obtained by the following equation (3), and the rotational phase angle θ is obtained by integrating the rotational speed ω. Here, G1 is the reciprocal of the induced voltage constant of the motor 15, and G2 is a gain constant.
ω = G1 / Eqs−G2 / Eds (3)
According to this estimation calculation, the rotational speed ω is obtained from the induced voltage estimated value Eqs, and the induced voltage estimated value Eds is controlled to converge to 0, so that the rotational phase angle (magnetic pole position) θ is It works to match the actual rotational position.

  The magnetic pole position estimator 39 determines the magnetic pole position of the rotor 19 that is determined according to the voltage command values Vd and Vq output from the winding resistance detector 47 when the permission signal Sp is at the H level (when the motor is stopped). θ0 is output.

  The control microcomputer 36 reads the resistance R calculated by the winding resistance detector 47 and also reads the induced voltage Ed and the rotational speed ω calculated inside the magnetic pole position estimator 39. Further, the control microcomputer 36 reads the d-axis voltage command value Vd and the q-axis voltage command value Vq from the proportional integrators 44 and 45 and also reads the d-axis current value Id and the q-axis current value Iq from the coordinate converter 46. It is like that. Based on these values, as will be described later, switching control of relays (changeover switches) 62 to 64 arranged for switching the connection of the stator winding 18 of the motor 15 is performed.

  FIG. 2 shows the configuration of the stator winding 18 portion of the motor 15. The stator winding 18 includes windings 61U, 61V, 61W corresponding to the three-phase AC power supplied from the inverter circuit 37, respectively. That is, the U, V, W phase output terminals of the inverter circuit 37 are connected to one ends of the windings 61U, 61V, 61W, respectively.

  On the other hand, the other ends of the windings 61U, 61V, and 61W are connected to movable contacts of relays (corresponding to changeover switches) 62, 63, and 64, respectively. The relays 62, 63, 64 have one fixed contact on the Y (star) connection side and the other fixed contact on the Δ (delta) connection side. The switching of the contacts of the relays 62 to 64 is controlled by the control microcomputer 36 as in the relays of the first embodiment. The Y connection side contacts of the relays 62 to 64 are connected in common. On the other hand, the Δ connection side contacts of the relays 62, 63, 64 are connected to the W-phase, U-phase, and V-phase output terminals of the inverter circuit 37, respectively.

  Next, the operation of this embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing the contents of control by the control microcomputer 36 for the portion related to the gist of the present invention. In the initial state when the power is turned on, the control microcomputer 36 connects the movable contacts of the relays 82 to 84 to the Y connection side contacts as shown in FIG. 2A, and the windings 61U to 61W of the motor 15 are connected. Are in Y-connection. In that state, the washing operation is started.

<Transition from washing or rinsing operation to dehydration operation>
The control microcomputer 36 sets the permission signal Sp to L level (inactive), gradually increases the command rotational speed ωref from 0, and starts the motor 15. After starting the motor 15, the magnetic pole position estimator 39 includes the d-axis current value Id and q-axis current value Iq output from the coordinate converter 46, and the d-axis voltage command value Vd output from the proportional integrators 44 and 45. And q-axis voltage command value Vq, motor constants Ld and Lq, and winding resistance R obtained by winding resistance detector 47, and based on the above-mentioned formulas (1) to (3), rotation speed ω and rotation The phase angle θ is obtained. The control microcomputer 36 performs forward / reverse operation of the drum 8 (that is, the motor 15) according to a predetermined pattern in the washing operation and the rinsing operation.

  When the washing operation is completed, the control microcomputer 36 issues a winding switching command (step S1), and determines whether the rotation of the motor 15 is stopped (rotation speed ω = 0 or induced voltage Ed = 0). (Step S2). When the rotation stop is detected (“YES”), the winding resistance detector 47 applies a predetermined voltage to the winding (step S3) and obtains the winding resistance R in the state before switching (step S4).

Here, the voltage / current equation of the permanent magnet synchronous motor 15 is expressed by the following equation (4) for the d-axis.
Ed = Vd−R · Id + ω · Lq · Iq (4)
When the motor 15 is stopped, since the rotational speed ω = 0 and the d-axis induced voltage Ed = 0, the following equation (5) is obtained from the equation (4).
R = Vd / Id (5)
That is, when the motor 15 is stopped, the winding resistance R can be obtained by detecting the d-axis voltage Vd and the d-axis current Id.

  That is, in step S3, the control microcomputer 36 sets the permission signal Sp to the H level. Then, the winding resistance detector 47 outputs a d-axis voltage command value Vd and a q-axis voltage command value Vq having a predetermined magnitude. However, the q-axis voltage command value Vq is 0. The coordinate converter 48 receives the voltage command values Vd and Vq from the winding resistance detector 47 and performs rotational coordinate conversion based on the magnetic pole position θ0 output from the magnetic pole position estimator 39. As a result, a current according to the d-axis voltage command value Vd flows through the winding 18 of the motor 15 via the inverter circuit 37.

  When the d-axis current is supplied to the winding 18 in this manner, the effect that the rotor 19 is fixed at a predetermined position and the motor 15 is easily started is produced. The winding resistance detector 47 receives the d-axis current value Id from the coordinate converter 46 in a state where the rotor 19 is fixed, and obtains the winding resistance R by the above equation (5). The d-axis current detection value Id at this time may be obtained using only one A / D conversion value, but if there is a possibility that an error occurs in the A / D conversion value due to the influence of noise, a plurality of d-axis current detection values Id may be obtained. It is preferable to obtain the average value of the A / D conversion values. The resistance value of the winding obtained in step S4 is RB.

  Subsequently, in order to start the dehydrating operation, the control microcomputer 36 connects the movable contacts of the relays 62 to 64 to the Δ connection side contacts as shown in FIG. 2B, and connects the windings 61U to 61W to the Δ connection. Connect (step S5). Thus, by switching the connection state of the windings 61U to 61W from the Y connection to the Δ connection, the number of windings contributing to generation of the induced voltage generated in the windings 61U to 61W becomes √3: 1. Accordingly, the motor 15 is driven to rotate in a state suitable for low-speed high-torque driving because the number of windings contributing to generation of the induced voltage is increased during the washing operation in step S1. Further, the motor 15 is driven to rotate in a state suitable for high-speed low-torque driving because the number of windings contributing to generation of the induced voltage is reduced during the dehydrating operation.

  However, before actually starting the dehydration operation, the control microcomputer 36 again measures the winding resistance R in the same manner as in steps S3 and S4 (steps S6 and S7), and the resistance value obtained here is calculated. RA. Then, the resistance values RB and RA obtained in steps S4 and S6 are compared (step S8), and it is determined whether or not there is a predetermined difference between the two (step S9). That is, when the stator winding 18 is switched from the Y-connection to the Δ-connection, the resistance values before and after the switching should be compared, so that RB> RA should be satisfied. Therefore, the control microcomputer 36 determines whether the stator winding 18 is actually switched from the Y connection to the Δ connection according to the comparison result of the resistance values.

  In step S9, if there is a sufficient difference between the resistance values RB and RA (“mismatch”, “YES”), this indicates that the stator winding 18 has been switched by Δ connection. The process is terminated (step S10) and the dehydrating operation is started. On the other hand, if there is not a sufficient difference between the resistance values RB and RA (“NO”), it is estimated that the stator winding 18 is not switched to the Δ connection due to, for example, a failure of the relays 62 to 64. Therefore, in this case, error processing is performed ("switching error", step S11). Then, the process returns to step S1 to issue a coil switching command again and retry the coil switching. Here, “error processing” is processing for displaying an error code indicating “coil switching abnormality” on the display unit of the operation panel 4, for example.

<Dehydration operation: Transition from low speed area to high speed area>
In this case, unlike the above example, winding switching is not performed while the motor 15 is stopped, and switching is performed while the rotational speed of the motor 15 shifts from the low speed region to the high speed region in the middle of starting the dewatering operation. Do. The switching threshold is set to about 100 rpm, for example. That is, when the rotation speed of the motor 15 reaches 100 rpm, the control microcomputer 36 issues a winding switching command in step S1, determines “YES” in step S2, and proceeds to step S12.

  In an actual washing machine, if the winding is switched in one product, the motor 15 is either stopped or rotating, but in order to show the versatility of the rotating machine drive system of the present invention, In the flow of FIG. 4, both cases are described in an integrated manner.

  In step S12, the control microcomputer 36 compares the DC voltage VDC generated and output by the converter 53 with the induced voltage Ed at that time, and if VDC> Ed (step S13, “YES”), the process proceeds to step S14. Transition. On the other hand, if VDC ≦ Ed (“NO”), it is presumed that there is some abnormality in the motor 15, so it is determined that winding switching is not possible (step S25), and error processing is performed (step S26).

  In step S14, the control microcomputer 36 calculates (refers to) the induced voltage Ed at that time to obtain Ed_B, and obtains the rotational speed ωB of the motor 15, and all the six IGBTs 50 constituting the inverter circuit 37 are obtained. It is turned off (step S15). Then, the rotor position cannot be estimated by the magnetic pole position estimator 39 (step S16).

  Subsequently, in order to protect the relays 62 to 64, the control microcomputer 36 waits until the detected motor currents Iv and Iw become zero (step S17, “YES”). The movable contacts 62 to 64 are connected to the Δ connection side contacts, and the windings 61U to 61W are switched from the Y connection connection to the Δ connection connection (step S18). Then, the switching control by the inverter circuit 37 is restarted, the current command values Iqref and Idref are set to zero, PI control (proportional integral control) is performed until there is no deviation from the detected currents Id and Iq, and the motor current is controlled to zero. (Step S19).

Then, the rotor position can be estimated by the magnetic pole position estimator 39 (step S20), and the control microcomputer 36 calculates the induced voltage Ed at that time to Ed_A and obtains the rotation speed ωA of the motor 15. (Step S21). Then, the ratio Ed / ω between the induced voltage and the motor rotational speed before and after switching of the winding 18 is compared (step S22).
If Ed_B / ωB ≠ Ed_A / ωA (step S23, “YES”), it is determined that the winding has been switched normally, and the switching process is terminated (step S24). On the other hand, if Ed_B / ωB≈Ed_A / ωA (step S23, “NO”), it is determined that the winding is not switched, and the process proceeds to step S26. That is, in the case of a motor having the same configuration, the induced voltage Ed is a function showing a linearity with respect to the rotational speed, so the ratio between the induced voltage and the rotational speed is compared.

As described above, according to this embodiment, when the connection state of the stator winding 18 of the motor 15 is changed by the relays 62 to 64 and the induced voltage constant of the winding 18 is switched, the control microcomputer 36 It was confirmed that the connection state of the winding 18 was changed. Specifically, when the motor 15 is stopped, the change result is confirmed by comparing changes in the resistance value of the winding 18 before and after the relays 62 to 64 are operated. When the motor 15 is rotating, the relays 62 to 64 are checked. Before and after the operation, the change of the induced voltage Ed estimated by the magnetic pole position estimator 39 is compared and confirmed.
Therefore, in any case, it is possible to confirm whether or not the connection state of the winding 18 has changed, and it is possible to prevent the motor 15 from operating without actually changing the connection state. And each operation | movement can be normally performed by applying to the washing machine which performs washing | cleaning or a rinsing operation and a spin-drying | dehydration operation using one motor.

  In addition, during the rotation of the motor 15, if the difference between the DC voltage input to the inverter unit 37 and the induced voltage Ed at that time is within a predetermined value, the control microcomputer 36 rotates the motor 15 rotation speed ωB and After acquiring the pre-switching induced voltage Ed_B, all the IGBTs 50 constituting the inverter unit 37 are turned OFF, and when it is detected that the winding current of the motor becomes zero, the open / close state of the relays 62 to 64 is changed, Control is performed so that the winding current becomes zero again, the rotational speed ωA at that time and the induced voltage Ed_A after switching are acquired, and switching confirmation is performed by comparing Ed_B / ωB and Ed_A / ωA. Therefore, even if the motor 15 is rotating, it is possible to reliably check the switching result.

Then, the ratio between the induced voltage and the rotational speed is compared to determine whether or not the ratio is inconsistent. Therefore, after switching the winding 18, the time required to make the current zero, the inertia of the motor 15, etc. Even when the rotational speed of the motor 15 varies greatly depending on the magnitude of the moment, the switching determination of the winding 18 can be performed more accurately.
Furthermore, since the connection state of the winding 18 is switched between the washing operation and the dehydration operation, the induced voltage constant of the winding 18 can be changed so as to be optimal according to the respective operation characteristics. In addition, since the connection state of the winding 18 is switched between a low-speed rotation region and a high-speed rotation region during the dehydration operation, a wide range of rotational changes during the dehydration operation can be performed in a region where the rotation speed is actually high. The induced voltage constant of the winding 18 can be appropriately changed.

The present invention is not limited to the above embodiment, and can be modified or expanded as follows.
The number of the plurality of windings connected in series may be changed. Further, the tap to be selected for one winding may be switched.
Only one of the method of switching while the motor is stopped and the method of switching while rotating may be implemented.
If it is assumed that the rotation speed of the motor 15 does not change significantly after the winding 18 is switched, only the induced voltages Ed_B and Ed_A are detected in steps S14 and S21 in FIG. 4, and in steps S22 and S23. The induced voltages Ed_B and Ed_A may be compared to determine whether or not they are inconsistent.
Other power MOSFETs or power transistors may be used for the semiconductor switching element.
The induced voltage constant of the winding may be changed in three stages or more.
You may apply not only to a drum type but to a vertical washing machine.
Further, the present invention is not limited to a washing machine, and can be widely applied to any device that needs to greatly change the driving characteristics of a rotating machine.

FIG. 1 is a functional block diagram showing a configuration of a control device according to an embodiment when the present invention is applied to a drum type washing machine. Diagram showing the switching state of windings The figure which shows the whole structure of a drum type washing machine The flowchart which shows the control contents by the microcomputer for control about the part which concerns on the summary of this invention The figure which shows each driving | running state of a washing machine, and the characteristic requested | required of a motor about them

Explanation of symbols

  In the drawings, 1 is a washing machine, 15 is a motor (rotor), 18 is a stator winding, 19 is a rotor (rotor), 36 is a control microcomputer (switching result confirmation means, stop time confirmation means, drive time confirmation) Means), 37 is an inverter circuit (power conversion means), 39 is a magnetic pole position estimator (drive-time confirmation means, position estimation means), 47 is a winding resistance detector (stop-time confirmation means), and 50 is an IGBT (semiconductor switching). Elements) 62 to 64 represent relays (changeover switches).

Claims (13)

A rotating machine configured to have a plurality of induced voltage constants by changing a connection state of the stator winding;
A changeover switch for changing the connection state of the windings;
A rotating machine drive system comprising: a switching result confirmation means for controlling opening and closing of the changeover switch and confirming that the connection state of the winding has been changed by the control.   2. The switching result confirming unit includes a stop-time confirming unit that performs confirmation while the rotating machine is stopped, and a driving-time confirming unit that performs confirmation during driving of the rotating machine. The rotating machine drive system described.   3. The rotating machine drive system according to claim 2, wherein the stop-time confirmation means confirms a switching result by comparing a change in resistance value of the winding before and after the change-over switch is operated. A position estimating means for detecting a current of the winding and estimating a rotor position of the rotating machine by estimating an induced voltage generated in the winding based on the current;
3. The driving time confirming unit confirms a switching result by comparing a change in induced voltage of the winding estimated by the position estimating unit before and after operating the changeover switch. Or the rotating machine drive system according to 3. Power conversion means having a semiconductor switching element and outputting a voltage corresponding to the switching state to the stator winding,
The driving time confirmation means includes
If the difference between the input voltage to the power conversion means and the induced voltage is within a predetermined value, the power conversion means is configured after referring to the induced voltage (pre-switching voltage) of the rotating machine at that time. Turn off the semiconductor switching element,
Upon detecting that the winding current has become zero, change the open / close state of the changeover switch,
Again, when detecting that the winding current has become zero, refer to the induced voltage (voltage after switching) of the rotating machine at that time,
The rotating machine drive system according to claim 4, wherein the pre-switching voltage and the post-switching voltage are compared. When the driving time checking means refers to the pre-switching voltage and the post-switching voltage, it also refers to the rotational speed of the rotating machine at that time,
6. The rotating machine drive system according to claim 5, wherein the ratio between the pre-switching voltage and the rotational speed at that time is compared with the ratio between the post-switching voltage and the rotational speed at that time.   A washing machine comprising the rotating machine drive system according to any one of claims 1 to 6, wherein a washing operation and a dehydrating operation are performed by a driving force generated by the rotating machine.   The washing machine according to claim 7, wherein the connection state of the winding is switched between the washing operation and the dehydration operation.   The washing machine according to claim 7 or 8, wherein the connection state of the winding is switched between a low-speed rotation region and a high-speed rotation region during the dehydration operation. About the rotating machine configured to have a plurality of induced voltage constants by changing the connection state of the stator winding by the changeover switch,
When the rotation of the rotating machine is stopped, the switching result of the rotating machine is confirmed by comparing the change of the resistance value of the winding before and after the changeover switch is operated. Result confirmation method. About the rotating machine configured to have a plurality of induced voltage constants by changing the connection state of the stator winding by the changeover switch,
In order to drive and control the rotating machine, the current of the winding is detected when the rotating machine is rotating, and the rotation of the rotating machine is estimated by estimating the induced voltage generated in the winding based on the current. When estimating the child position,
A method for confirming a result of switching the winding of a rotating machine, wherein the result of switching is confirmed by comparing the estimated change in the induced voltage of the winding before and after the switch is operated. In the case of including a semiconductor switching element and including power conversion means for outputting a voltage corresponding to the switching state to the stator winding,
If the difference between the driving power supply voltage and the induced voltage is within a predetermined value, the semiconductor switching element that constitutes the power conversion means is referred to after referring to the induced voltage (voltage before switching) of the rotating machine at that time. Turn it off,
Upon detecting that the winding current has become zero, change the open / close state of the changeover switch,
Again, when detecting that the winding current has become zero, refer to the induced voltage (voltage after switching) of the rotating machine at that time,
The winding switching result confirmation method for a rotating machine according to claim 11, wherein the pre-switching voltage and the post-switching voltage are compared. When referring to the pre-switching voltage and the post-switching voltage, also refer to the rotational speed of the rotating machine at that time,
13. The method for confirming the result of switching the winding of the rotating machine according to claim 12, wherein the ratio between the pre-switching voltage and the rotational speed at that time is compared with the ratio between the post-switching voltage and the rotational speed at that time.

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